Protein quaternary structureProtein quaternary structure is the fourth (and highest) classification level of protein structure. Protein quaternary structure refers to the structure of proteins which are themselves composed of two or more smaller protein chains (also referred to as subunits). Protein quaternary structure describes the number and arrangement of multiple folded protein subunits in a multi-subunit complex. It includes organizations from simple dimers to large homooligomers and complexes with defined or variable numbers of subunits.
Conserved non-coding sequenceA conserved non-coding sequence (CNS) is a DNA sequence of noncoding DNA that is evolutionarily conserved. These sequences are of interest for their potential to regulate gene production. CNSs in plants and animals are highly associated with transcription factor binding sites and other cis-acting regulatory elements. Conserved non-coding sequences can be important sites of evolutionary divergence as mutations in these regions may alter the regulation of conserved genes, producing species-specific patterns of gene expression.
Evo-devo gene toolkitThe evo-devo gene toolkit is the small subset of genes in an organism's genome whose products control the organism's embryonic development. Toolkit genes are central to the synthesis of molecular genetics, palaeontology, evolution and developmental biology in the science of evolutionary developmental biology (evo-devo). Many of them are ancient and highly conserved among animal phyla. Toolkit genes are highly conserved among phyla, meaning that they are ancient, dating back to the last common ancestor of bilaterian animals.
PatternA pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated like a wallpaper design. Any of the senses may directly observe patterns. Conversely, abstract patterns in science, mathematics, or language may be observable only by analysis. Direct observation in practice means seeing visual patterns, which are widespread in nature and in art.
Protein familyA protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity.
